It might feel like handing your taxes over to an accountant means it’s all their responsibility – but that’s not how HMRC sees it.
Even if they do all the legwork and file the return for you, you’re still the one legally on the hook.
If something’s wrong, or it’s submitted late, HMRC won’t be chasing your accountant – they’ll be chasing you.
This article looks at what can go wrong, what your options are if you’re hit with a penalty, and how to stay one step ahead next time around.
So who gets the blame if there’s a mistake?
HMRC doesn’t care who filled in the boxes. As far as they’re concerned, it’s your name on the return, so it’s your responsibility to check the details before it’s sent.
This applies whether you’re:
- A sole trader
- In a partnership
- A limited company director
Even if your accountant uses their agent login to file your return, you’re the one who’ll be fined if something’s wrong. That’s why it’s so important to understand what’s going in, even if you’re paying someone else to do it.
HMRC spells it out here: Self Assessment penalties explained.
What kind of mistakes can happen?
Most accountants are careful and accurate, but errors can and do slip through. Common ones include:
- Misreporting business income or forgetting to include all sources
- Leaving out an expense you sent them
- Filing late without telling you
- Entering the wrong figures for pension contributions or allowances
- Claiming something you’re not actually entitled to
Sometimes it’s a communication issue. You thought they were still working on your return, but they already submitted it. Or maybe you assumed they chased something with HMRC, when they didn’t.
What should you do if there’s a penalty?
If HMRC has issued a fine and you believe it’s down to your accountant, don’t panic — but don’t ignore it either.
Start by getting the facts straight:
- Ask your accountant when the return was submitted
- Check what figures they used — and what you gave them
- See if the error came from your side (e.g. missing info) or theirs
If they admit they got it wrong, they may offer to pay the penalty or at least contribute towards it. Not all firms will, but it’s worth asking – especially if they’ve made a clear mistake.
You may also be able to appeal the penalty if you’ve got a genuine excuse. Details here: Appeal a tax decision – GOV.UK
What if they don’t take responsibility?
Not all accountants will admit to it. Some may argue they did what they were told, or that it was your job to check the figures.
If you’re not making progress, review your original engagement letter or contract. This should explain what the accountant agreed to do and whether they’re covered by professional indemnity insurance.
If they’re a member of a professional body, you can take your complaint further:
In more serious cases — where you’ve suffered a financial loss — you could speak to a solicitor or raise a claim through the Financial Ombudsman Service if they’re a regulated adviser.
Could tax investigation insurance cover this?
If the mistake leads to an enquiry from HMRC, you might find yourself needing extra help, especially if it drags on. In these situations, tax investigation insurance can be a lifesaver.
It won’t cover the tax itself, but it may pay for your accountant’s time to respond to HMRC, chase records, and defend your position. Without cover, you’d be paying those fees out of pocket, even if the error wasn’t yours.
How to avoid problems in the future
The best protection is being more involved. Here’s what you can do:
- Ask to see the return before it’s filed. Double-check income and expenses line by line.
- Submit your records early. The more time your accountant has, the less likely they’ll rush or miss something.
- Keep communication clear. Confirm who is responsible for what, especially regarding deadlines.
- Stick with accountants who explain things properly. If they’re vague or evasive, consider switching.
If you’re thinking about making a change, we’ve got a full guide on how to switch accountants the right way.
Summary
If your accountant makes a mistake, it’s frustrating, but HMRC will still treat it as your problem to solve. That’s why it pays to stay involved, ask questions, and make sure you’ve got a written agreement in place that sets out what’s expected on both sides.
More on working with an accountant: do you really need one as a sole trader?
From £37.50/m
From £49/m